This invention relates to a device for drawing bilge water from a water jet propelled watercraft and more particularly to an improved bilge water discharge system for a watercraft.
One very popular type of watercraft is powered by a jet propulsion unit. The jet propulsion unit includes an impeller that is driven by a powering engine and which draws water from the body of water in which the watercraft is operating in and discharges it so as to provide a propulsion force for the watercraft. With this type of watercraft, it has been a practice to employ the jet propulsion unit as a means for drawing bilge water from the hull of the watercraft. For example, as shown in U.S. Pat. No. 3,826,220, issued July 30, 1974 in the name of Clarence Jacobson, and in Japanese Patent No. Sho 52-14920, there are shown systems wherein the water jet propulsion unit is employed as an arrangement for generating a negative pressure to draw bilge water from the hull of the watercraft and discharge it back into the body of water through the jet propulsion unit. Although these systems are advantageous for removing the bilge water, they decrease the efficiency of the jet propulsion unit. For example, they require either the provision of a reduced diameter section in the jet propulsion unit so as to create a venturi effect or a nozzle that extends into the flow path through the jet propulsion unit. Either system causes the watercraft to lose efficiency in its jet pump. This is a result from the restriction to water flow through the jet propulsion unit caused by either the venturi section and/or the protruding nozzle.
It is, therefore, a principal object of this invention to provide an improved system for removing bilge water in a jet propelled vehicle which system does not reduce the efficiency of the jet propulsion unit.
It is a further object of this invention to provide an improved and simplified arrangement for removing bilge water in a jet propelled vehicle wherein the performance of the watercraft is not altered.
It is also desirable for the bilge water removing system to provide some way in which the watercraft operator can ascertain that all of the bilge water has been removed. For example, in conditions such as racing, it is important for the operator to know that the bilge is clear of water.
It is, therefore, a further object of this invention to provide a bilge water removing system for a watercraft in which the operator is given a visual indication that all bilge water has been removed.
It is another object of this invention to provide a bilge water removal system for a watercraft wherein the operation of the watercraft per se assists in the removal of the bilge water.
In watercraft powered by inboard mounted internal combustion engines, there is a difficulty in designing an effective system for discharge the exhaust gases to the atmosphere without causing difficulties due to the exhaust heat and its proximity to the hull.
It is a still further object of this invention to provide a bilge water removing system which is effective in further cooling the exhaust gases of the inboard mounted engine.